Numerical Modeling of Steam-Gas Flow in NPP Containment with VVER and Passive Heat Removal

The main elements of a mathematical model and test results for the specialized code PGS-TK to be used for calculating the flow of a multicomponent steam–gas mixture in the containment of a power-generating unit in NPP with passive heat-removal and volumetric and surface condensation of steam are presented. It is shown that owing to the modern mathematical models and numerical methods the code makes it possible to perform accurate calculations of the containment temperature and pressure for an unanticipated accident without using any adjustable parameters or specific experimental approximations.